This paper analyses, within a standard International Environmental Agreement game, the effect of the introduction of adaptation on climate negotiation. The model expands the existing literature by considering a double relation between the two strategies. The common assumption that higher mitigation decreases the marginal benefit of adaptation and vice versa is enriched allowing for the possibility that mitigation, leading to lower and more manageable damages, determines a greater effectiveness of adaptive measures. We find the possibility for adaptation and mitigation to be strategic complements and not, as commonly believed, substitutes. Yet, as already known from the literature, the presence of adaptation can determine upward-sloping mitigation reaction functions regardless of the strategic relationship between mitigation and adaptation. When this is the case, the grand coalition can form. Nonetheless, large participation can induce substantive welfare gains only if adaptation and mitigation are strategic complements.

本文在标准的《国际环境协议》博弈中分析了引入适应措施对气候谈判的影响。该模型通过考虑两种策略之间的双重关系来扩展现有文献。较高的缓解程度会降低适应的边际收益的普遍假设，反之亦然，这一假设得到了丰富，从而使得缓解的可能性降低，从而导致损害的减少和可控性的提高，从而决定了适应措施的有效性。我们发现适应和缓解的可能性是战略性补充，而不是通常认为的替代品。然而，如从文献中已经知道的，适应的存在可以确定向上倾斜的缓解反应功能，而与缓解和适应之间的战略关系无关。在这种情况下，可以形成大联盟。但是，只有在适应和缓解成为战略补充时，大量参与才能带来实质性的福利收益。